Simplify build jobs with anchors (#2938)

.github/workflows/ci-push.yml

@@ -2,13 +2,7 @@ name: CI
 
 on: [push]
 
-jobs:
+.build-strategy: &build-strategy
-  
-# Build jobs
-# These jobs build each Racket component separately and tests on the component start as soon as each
-# component finishes building.
-
-  build-racketcgc:
   strategy:
     fail-fast: false
     matrix:
@@ -16,13 +10,11 @@ jobs:
       cify: [cify, nocify]
           
   runs-on: ${{ matrix.os }}
+
   env:
     RACKET_EXTRA_CONFIGURE_ARGS: ""
 
-    steps:
+.build-setup-extra-flags: &build-setup-extra-flags
-    - uses: actions/checkout@v1
-      with:
-        fetch-depth: 100
   - name: Setup OS specific configure args
     if:  runner.os == 'macOS'
     run: echo "::set-env name=RACKET_EXTRA_CONFIGURE_ARGS::--enable-macprefix $RACKET_EXTRA_CONFIGURE_ARGS"
@@ -32,6 +24,21 @@ jobs:
   - name: Setup cify if disabled
     if: matrix.cify == 'nocify'
     run: echo "::set-env name=CIFY_OPTION::--disable-cify"
+
+jobs:
+  
+# Build jobs
+# These jobs build each Racket component separately and tests on the component start as soon as each
+# component finishes building.
+
+  build-racketcgc:
+    <<: *build-strategy
+    
+    steps:
+    - uses: actions/checkout@v1
+      with:
+        fetch-depth: 100
+    <<: *build-setup-extra-flags
     - name: Configuring Racket CGC
       working-directory: ./racket/src
       run: >
@@ -64,32 +71,14 @@ jobs:
         path: ../racketcgc-${{ matrix.os }}-${{ matrix.cify }}-x64_git${{ github.sha }}.tar.bz2
 
   build-racket3m:
-    strategy:
+    <<: *build-strategy    
-      fail-fast: false
-      matrix:
-        os: [ubuntu-18.04, macos-latest]
-        cify: [cify, nocify]
-            
-    runs-on: ${{ matrix.os }}
-    
     needs: build-racketcgc
     
-    env:
-      RACKET_EXTRA_CONFIGURE_ARGS: ""
-    
     steps:
     - uses: actions/checkout@v1
       with:
         fetch-depth: 100
-    - name: Setup OS specific configure args
+    <<: *build-setup-extra-flags
-      if:  runner.os == 'macOS'
-      run: echo "::set-env name=RACKET_EXTRA_CONFIGURE_ARGS::--enable-macprefix $RACKET_EXTRA_CONFIGURE_ARGS"
-    - name: Setup cify if enabled
-      if: matrix.cify == 'cify'
-      run: echo "::set-env name=CIFY_OPTION::--enable-cify"
-    - name: Setup cify if disabled
-      if: matrix.cify == 'nocify'
-      run: echo "::set-env name=CIFY_OPTION::--disable-cify"
     - uses: actions/download-artifact@master
       with:
         name: racketcgc-${{ matrix.os }}-nocify-x64_git${{ github.sha }}
@@ -129,17 +118,9 @@ jobs:
         path: ../racket3m-${{ matrix.os }}-${{ matrix.cify }}-x64_git${{ github.sha }}.tar.bz2
 
   build-racketcs:
-    strategy:
+    <<: *build-strategy
-      fail-fast: false
-      matrix:
-        os: [ubuntu-18.04, macos-latest]
-            
-    runs-on: ${{ matrix.os }}
     needs: build-racketcgc
           
-    env:
-      RACKET_EXTRA_CONFIGURE_ARGS: ""
-      
     steps:
     - uses: actions/checkout@v1
       with: